Safety elevator



March 20, 1951 R, GAMMELL 2,545,457

SAFETY ELEVATOR Filed Nov. '50, 1949 INVENTOR Robert M GCLTILflZBlL.

ATTORNEY Patented Mar. 20, 1951 UNITED STATES PATENT OFFHCE I 2,545,457 SAFETY ELEVATOR I Robert M. Gammell, Spokane, Wash.

Application November 30, 1949, Serial No. 130,086 Claims. (01. 18785) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370' 0. G. 757) The invention described herein may bemanufactured and used by or for the Government of the United States for governmental purposes without payment to me of any royalty thereon in accordance with the provisions of the act of April 30, 1928 (ch. 460, 45 Stat. L. 467).

This invention relates to an elevator or lift of the type employed in mine shafts and which comprises essentially a body or cage lifted and lowered by a single power-operated cable. The principal object of the invention is to provide an elevator of this type with means to preclude falling of the body or cage upon rupture or accidental slackening of the cable.

Another object of the invention is to provide safety means for such an elevator consisting of abutment members normally retained within the body lines of the elevator and adapted to be acmeans described herein and illustrated in the accompanying drawings in which:

Figure 1 is a side elevational view of an elevator or lift provided with the safety means of the present invention.

Figure 2 is a view taken on a line 22 in Figure 1.

Figure 3 is a detail perspective view of one of the abutment members of the invention and the actuating piston unit associated therewith.

sociated means forming parts of the elevator.

Figure 5 is a detail view of" the value of this invention employed for actuating the abutment members forming the safety features of the present invention.

In greater detail and with refe ence to the drawings: 1

The elevator body 6, as shown in Figure 1, may be of standard construction comprising sides 6 and 1, the floor or bottom 8, and a top portion 9 including transverse strengthening rods l0. Bridle or lift members H project above the cage or body and are centrally engaged, as at 12, by an elongated link l3 to which, as at M, the outer end of a power-driven cable is fastened.

Figure 4 is a detail view of the lift bridle and as.--.

Secured to the under face of the floor or bottom 8 is a reinforced air pressure tank l6 capable of withstanding a considerable air pressure, for example, a GOO-pound air pressure. This tank may-rest upon transverse support members I! extending between the extreme lower ends of the sides 6 and 1 of the cage, as at l8. On each side of the tank IS a heavy support beam 19 and 20, respectively, extends, beingsecured to the bottom 8 of the cage by means of straps 2|. Upon these support beams l9 and. 20 are mounted reinforced cylinders 22-232425, each pair of cylinders being disposed in-endwise relationship.

Each cylinder has associated therewith-a piston, 26, 21, 28 and 29, respectively. As will be seen, particularly in Figure 3, each of the pistons, such as piston 25, has a threaded and therefore, adjustable) endwise connection with an upstanding lug 30 projecting upwardly of the base 3| 'of an abutment rail or shaft 32, slidably mounted between a pair of channel members 33 secured upon or forming part of the upper portions of the support beams l9 and 20.

An air' conduit 34 communicates as at 35 with the reservoir or tank [6 on the bottom of the elevator and proceeds to the top portion thereof where it has associatedtherewith an air valve 36 comprising an operating arm 31. A pressure gauge 41 may be interposed in line 34 at a convenient location for checking the pressure in tank IS. The upper end of arm 31, as will be seen in Figure 5, is connected by a short rod or cable 38 with the lower end of the link [3 and the normal tension of the elevator cable I5 is operative upon the link-and the rod 38 for normally holding the valve arm 31 in an upward or closed position. It will be noted in this connection that the link I3 (Figure 4) is formed with an elongated openingor slot for the purpose of permitting free and unhindered movement of the engaged portions !2 of the lift bridle l I therein, upon loosening or parting of the power cable l5.

,7 The valve 36 communicates with and is adapted to feed into each of the piston cylinders 22, 23, 24, and 25 by means of suitable conduits 39 and 40 (Figure 5) extending downwardly of each side of the mine cage and bifurcated at their lower ends for entering the adjacent cylinders at similar points indicated at 46 (Figures 2 and 3).

The valve handle 31 has secured thereto one end of a compression spring 42 (Figures 1 and 5), the other end of which is fastened to a cross strut 43 at the upper portion of the elevator body or lift. This spring 42 urges the handle 31 downwardly and the valve to a closed position, but its tension is normally overcome by that of the short 3 rod 38 and the lift cable l5 when these are at their normal tension.

Elevator shafts of the kind here contemplated are provided with horizontal wall beams such as those indicated at 44 and 45 (Figures 2 and 3). These wall beams project inwardly of the elevator shaft and are spaced relatively short distances apart in the vertical direction.

In the operation of this safety elevator, the abutment shafts 32 are normally disposed in an inward position so that the ends are well within the body lines of the elevator or cage. However, should the power cable [Ebeoome ruptured-or slackened, the spring 42 operates upon the valve handle 31 for instantly moving the latter downwardly and opening the valve 36, the link l3 affording the lift bridle I I with the necessary free movement for this operation. The opened valve immediately admits air pressure from reservoir vl6 into the cylinders 22, 23, 24,, and 2t, thereby projecting outwardly the pistons 25, 21, 28, and

1 '29, and the abutment shafts 32 associated with each of thepistons.

shafts are thus projected beyond thebody lines ;o'f the cage and extend into the path of the wall The ends of the abutment beams 44 and '45'at each end of the cage, coming to'rest against the next subjacent pair of these beams for instantly halting the elevator.

Modificationsof the invention will become apparent upon-consideration of the means herein disclosed, but these are believed to be comprised -within the spiritand scope of the invention.

- What is claimed is: 'l.'In -an elevator for a mine shaft provided with'spaced ;wall beams projecting inwardly of ;the s haft,'an elevator-body, a power-driven cable "yond the line of the elevator body into position for endwise contact with the subjacent wall beams to halt downward movement of the elevator body.

2. In an elevatonadaptedfor operation in an elevator shaftprovided with spaced wall beams projecting inwardly of the shaft, an elevator b,ody,-a power-driven cable forlifting and lowering the body, an air pressure reservoir on the body, piston units on the body connected with the reservoir for operation by air pressure therefrom,'valve means normally precluding such operation, abutment members connected with the piston units for movement thereby inwardly and outwardly of the body, and valve-actuating meagns associated with the cable and reservoir j for operation upon rupture or slackening of the -;cab1e tojeffect projection of the abutment members outwardly of the elevator body into position for abutting the subjacent wall beams to 'haltdownward movement of the elevator body. 3'. In an elevator adapted for operation in an j elevator shaftprovided with spaced wall beams projecting inwardly of the shaft, an elevator body, a power-driven cable for lifting and lowering the body, an air pressure reservoir on the bottom of the elevator body, piston units on said bottomand connected with the reservoir for operation by air pressure therefrom, abutment shafts connected with the piston units ,for movement therewith, a valve communicating with the reservoir, a valve arm connected with said cable and normally held thereby in position for retaining the valve closed, conduits from the valve to said piston units, and means operative upon rupture or slackening of the cable for actuating said arm to a valve-opening position to eifect operation of the piston units to project said abutment shafts outwardly of the elevator body for endwise contact upon the subjacent wall beams for halting downward movement of the elevator body.

4. In an elevator adapted for operation in an elevator shaft "provided with spaced wall beams ,projectinginwardly of the shaft, of an elevator body, a power-driven cable for lifting and lowering the body, an air pressure reservoir on the bottom of the elevator body, piston units on said bottom and connected with the reservoir for operation by air pressure therefrom, abutment shafts connected with the piston units for movement therewith, a valve communicating with the, reservoir, a valve arm connected with said cable and normally held thereby in position for retainingthe valve closed, conduits from the valve to said piston units, and a spring urging the valve arm toward valve-opening position and of a tension normally less than that of the cable, said spring being operative upon rupture or slackening of the cable for actuating said arm to a valve-opening position to effect operation of the piston units and project said abutment shafts outwardly of the elevator body for end- -wise contact upon the subjacent wall beams for halting downward movement of the elevator body.

5. In an elevator adapted for operation in an elevator shaft provided with spaced wall beams projecting inwardly of the shaft, an elevator body, a power-driven cable for lifting and lowering the body, a fluid pressure reservoir on the body, a piston unit'on the body connected with the reservoir for operation by pressure therefrom, valve means'normally precluding such operation, abutment members connected with the piston unit for movement thereby inwardly and outwardly of the body, and valve-actuating means associated with the cable and reservoir for operation upon rupture or slackening of the cable to effectprojection of the abutment members outwardly of the elevator body into position for, abutting the subjacent wall beams to .halt downward movement of the elevator body.

ROBERT M. GAMMELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 324,751 Curtiss Aug. 18, 1885 

